nhbb :: precision engineering :: shield & seal types

shield & seal types

Shields and seals are protective closures that retain lubricants and assist in preventing contaminants from reaching internal surfaces. In torque-sensitive applications, it may be advantageous to use shields rather than seals because there are no contacting surfaces to create drag. The following chart illustrates the more common types of shields and seals.

Consideration should be given to the compatibility of cage and shield type designs to allow for appropriate clearance. Consult with factory for availability.

Description	Type	Design	Material	Operating Temp Max.
Shield—Removable with snap wire. Minimal clearance. Most popular.	Z		Stainless Steel 300 Series	600°F
Seal with snap wire. Provide minimal clearance to light contact resulting in low torque.	L		Glass-reinforced PTFE	400°F
Seal—Excellent sealing characteristics.	D		Buna-N Bonded to Steel Insert	250°F
Seal—Excellent sealing characteristics. High cost.	D1		Viton Bonded to Steel Insert	400°F